Comment on WAI-ARIA 1.0 Authoring Practices document

On the following page: http://www.w3.org/TR/wai-aria-practices/
In section 2. General Steps for Building an Accessible Widget with 
WAI-ARIA (http://www.w3.org/TR/wai-aria-practices/#accessiblewidget)
In point 3. Establish the widget structure in the markup (parent/child)
There is an example that has the following markup:

<div role="toolbar" tabindex="0" aria-activedescendant="button1">
  <img src="buttoncut.png" alt="cut" id="button1">
  <img src="buttoncopy.png" alt="copy" id="button1">
  <img src="buttonpaste.png" alt="paste" id="button1">
</div> 

I believe that you do not want to have three identical id's ("button1").
Instead, I believe you would prefer to have three different id's, like in 
the following:

<div role="toolbar" tabindex="0" aria-activedescendant="button1">
  <img src="buttoncut.png" alt="cut" id="button1">
  <img src="buttoncopy.png" alt="copy" id="button2">
  <img src="buttonpaste.png" alt="paste" id="button3">
</div> 

Keep up the good work!
Thanks,
Carolyn